This is not going to happen. It is a very rich, successful engineer musing at what might be possible if we thought radically different about transportation. I'm as big a fan of Elon Musk's projects as anyone, but the weight assigned to these napkin calculations is ridiculous.

[Edit: If anything, this might lead people to take this type of eccentric and radical design more seriously. But given the criticism Musk's engineering ventures have had before, I wouldn't count on it.]